At the simplest level of construction, all cells possess a few fundamental components despite varying significantly in size, shape, structure, and function. These components include a cytoplasm (a gel-like substance composed of water and dissolved chemicals needed for growth), a plasma membrane (also called a cell membrane or cytoplasmic membrane) that contains the cytoplasm, one or more chromosomes containing the genetic blueprints of the cell, and ribosomes which are organelles used for the production of proteins.